Dirk Krueger

CONSUMPTION AND SAVING OVER THE LIFE CYCLE: HOW IMPORTANT ARE CONSUMER DURABLES?

In this paper we investigate whether a standard life-cycle model in which households purchase nondurable consumption and consumer durables and face idiosyncratic income and mortality risk as well as endogenous borrowing constraints can account for two key patterns of consumption and asset holdings over the life cycle. First, consumption expenditures on both durable and nondurable goods are hump-shaped. Second, young households keep very few liquid assets and hold most of their wealth in consumer durables. In our model durables play a dual role: they both provide consumption services and act as collateral for loans. A plausibly parameterized version of the model predicts that the interaction of consumer durables and endogenous borrowing constraints induces durables accumulation early in life and higher consumption of nondurables and accumulation of financial assets later in the life cycle, of an order of magnitude consistent with observed data. (This abstract was borrowed from another version of this item.)

Inequality Trends for Germany in the Last Two Decades: A Tale of Two Countries

In this paper we first document inequality trends in wages, hours worked, earnings, consumption, and wealth for Germany from the last twenty years. We generally find that inequality was relatively stable in West Germany until the German reunification, and then trended upwards for wages and market incomes, especially after about 1998. Disposable income and consumption, on the other hand, display only a modest increase in inequality over the same period. These trends occurred against the backdrop of lower trend growth of earnings, incomes and consumption in the 1990s relative to the 1980s. In the second part of the paper we further analyze the differences between East and West Germans in terms of the evolution of levels and inequality of wages, income, and consumption.

Computing equilibrium in OLG models with stochastic production

Abstract In this paper we develop a projection algorithm to approximate equilibria in overlapping generations economies with a large number of generations and stochastic aggregate production. In these types of economies the state space includes the distribution of wealth across generations. We use Smolyaks algorithm to approximate policy functions, which map the current state into agents’ optimal choices, by linear combinations of polynomials. This allows us to compute equilibria for models where agents live for 20–30 periods. We also provide examples which demonstrate that approximating the cross-sectional wealth distribution only by its first moment (and thereby reducing the dimension of the state space to two continuous state variable, independently of the number of agents) often leads to very high relative errors in agents’ Euler equations.

Public Versus Private Risk Sharing

Can public insurance through redistributive income taxation improve the allocation of risk in an economy in which private risk sharing is limited? The answer depends crucially on the fundamental friction that limits private risk sharing in the first place. If risk sharing is incomplete because some insurance markets are missing for model-exogenous reasons (as in Bewley, 1986 and Aiyagari, 1994) publicly provided risk sharing via a tax system generally improves on the allocation of risk. If instead private insurance markets exist but their use is limited by the absence of complete enforcement (as in Kehoe and Levine, 1993 and Kocherlakota, 1996) then the provision of public insurance can crowd out private insurance to such an extent that total consumption insurance is reduced. By reducing income risk the tax system increases the value of being excluded from private insurance markets and hence weakens the enforcement mechanism of these contracts. In this paper we theoretically characterize and numerically compute equilibria in an economy with limited enforcement and a continuum of agents facing realistic income risk and tax systems with various degrees of risk reduction (progressivity). We find that the crowding-out effect of public insurance on private insurance in the limited enforcement model can be quantitatively important, as is the positive insurance effect of taxation in the Bewley model.

A DYNAMIC MODEL OF HOUSING DEMAND: ESTIMATION AND POLICY IMPLICATIONS*

Using data from the Panel Study of Income Dynamics (PSID) we specify, estimate and simulate a dynamic structural model of housing demand. Our model generalizes previous applied econometric work by incorporating realistic features of the housing market including non-convex adjustment costs from buying and selling a home, credit constraints from minimum downpayment requirements and uncertainty about the evolution of incomes and home prices. We argue that these features are critical for capturing salient features of housing demand observed in the PSID. After estimating the model we use it to simulate how consumer behavior responds to house price and income declines as well as tightening credit. These experiments are motivated by the U.S. recession starting in December of 2007 that saw large falls in home prices, large negative income shocks for many households and tightening credit standards. In the short run, relatively few households adjust their housing stock. Households respond instead by reducing non-housing consumption and reducing wealth because they wish to avoid losing their home and the associated adjustment costs. Households that adjust in the short run are those hit with a series of bad shocks, such as a negative income shock and a home price decline. A larger proportion of households do adjust their consumption in the long run, increasing their housing stock since housing is less expensive. However, such changes may occur several years after the shocks listed above.

On the Welfare Consequences of the Increase in Inequality in the United States

We investigate the welfare consequences of the stark increase in wage and earnings inequality in the United States over the last 30 years. Our data stems from the Consumer Expenditure Survey, which is the only U.S. dataset that contains information on wages, hours worked, earnings, and consumption for the same cross section of U.S. households. First, we document that, while the cross-sectional variation in wages and disposable earnings has significantly increased, the overall dispersion in consumption has not changed significantly. We also show that households at the bottom of the consumption distribution have increased their working hours to a larger extent than the rest of the population. To assess the magnitude and the incidence of the welfare consequences of these trends, we estimate stochastic processes for earnings, consumption, and leisure that are consistent with observed cross-sectional variability (both within and between education groups) and with household mobility patterns. In a standard lifetime utility framework, using consumption and leisure processes (as opposed to earnings processes) results in fairly robust estimates of these consequences. We find that about 60 percent of U.S. households face welfare losses and that the size of these losses ranges from 1 to 6% of lifetime consumption for different groups.

When is Market Incompleteness Irrelevant for the Price of Aggregate Risk (and When is it Not)

In a standard incomplete markets model with a continuum of households that have constant relative risk aversion (CRRA) preferences, the absence of insurance markets for idiosyncratic labor income risk has no effect on the premium for aggregate risk if the distribution of idiosyncratic risk is independent of aggregate shocks and aggregate consumption growth is independent over time. In equilibrium, households only use the stock market to smooth consumption; the bond market is inoperative. Furthermore, the cross-sectional distributions of wealth and consumption are not affected by aggregate shocks. These results hold regardless of the persistence of idiosyncratic shocks, even when households face tight solvency constraints. A weaker irrelevance result survives when we allow for predictability in aggregate consumption growth.

Housing and the Macroeconomy: The Role of Implicit Guarantees for Government-Sponsored Enterprises

This paper studies the macroeconomic effects of implicit government guarantees of the obligations of government-sponsored enterprises. We construct a model with competitive housing and mortgage markets in which the government provides banks with insurance against aggregate shocks to mortgage default risk. We use this model to evaluate aggregate and distributional impacts of this government subsidy of owner-occupied housing. Preliminary findings indicate that the subsidy leads to higher equilibrium housing investment, higher mortgage default rates, and lower welfare. The welfare effects of this policy vary substantially across members of the population with different economic characteristics.

Intergenerational Redistribution in the Great Recession

In this paper we construct a stochastic overlapping-generations general equilibrium model in which households are subject to aggregate shocks that affect both wages and asset prices. We use a calibrated version of the model to quantify how the welfare costs of severe recessions are distributed across different household age groups. The model predicts that younger cohorts fare better than older cohorts when the equilibrium decline in asset prices is large relative to the decline in wages, as observed in the data. Asset price declines hurt the old, who rely on asset sales to finance consumption, but benefit the young, who purchase assets at depressed prices. In our preferred calibration, asset prices decline more than twice as much as wages, consistent with the experience of the US economy in the Great Recession. A model recession is approximately welfare-neutral for households in the 20-29 age group, but translates into a large welfare loss of around 10% of lifetime consumption for households aged 70 and over.

Intergenerational Risk-Sharing via Social Security when Financial Markets Are Incomplete

This paper develops an overlapping generations model with stochastic production and incomplete markets to assess whether the introduction of an unfunded social security system can lead to a Pareto improvement, even if the initial equilibrium is neither production-ine±cient in the spirit of Diamond (1965) nor dynamically ine±cient in the spirit of Samuelson (1957). When returns to capital and wages are imperfectly correlated and subject to aggregate shocks, then the consumption variance of all generations can be reduced if private markets or government policies enable them to pool their labor and capital incomes. A social security system that endows retired households with a claim to labor income may serve as an e®ective tool to share aggregate risk between gener